Trailer un-square

[bigdodge88]

Just curious how ya'll that build trailers and scratch built bodies make things square? I know it sounds stupid but the trailer I attempted kind of twisted and bowed when I bonded the styrene panels together. Any suggestions?

Thanks,
Justin

[Old Busted Hotness]

It helps if you have something square you can set on the panels while the glue dries; even a pop can will work, as long as it's got a perpendicular surface and is heavy enough that it won't move.